This specification relates to verifying the authenticity of an input message based on a hashing algorithm.
Hashing algorithms can be used to create a “fingerprint” of a file or other data input. Hash functions can be used to create a hash value that can serve as an identifier of a file or other data. The hash value can be used as a shortcut for a lookup table or can be used for data comparison, e.g., to detect duplicate data or to verify that a particular file is an authentic copy of another file. In some cases, hash functions for different files can map to the same hash value, which results in a collision. Typically, it is desirable to minimize such collisions, so hash functions that have relatively high collision-resistance are generally preferable over less collision-resistant hash functions. It is typically also desirable that a hash function is resistant to creation of alternative messages that produce the same hash value. Examples of hashing algorithms include MD4 (message digest algorithm 4), MD5, SHA-1, and RIPEMD.